Special Equipment. Aceryic has a Staff of the Ivory Claw, though it has been corrupted. It drips in inky black energy, and deals necrotic damage on a spell crit rather than radiant.

Undead Fortitude. If damage reduces Aceryic to 0 hit points, he must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, Aceryic drops to 1 hit point instead.

Innate Spellcasting. Aceryic can innately cast the following spells, requiring no material components:

At will: Sapping Sting, Detect Magic, Misty Step

3/day each: Summon Undead, Blindness/Deafness (save DC 21)

Spellcasting. Aceryic is a 17th-level spellcaster that uses Intelligence as his spellcasting ability (spell save DC 21; +12 to hit with spell attacks). Aceryic has the following spells prepared from the wizard’s spell list:

Cantrips (at will): Mage Hand, Chill Touch, Mind Sliver, Eldritch Blast

1st Level (5 slots): Mage Armor, Inflict Wounds, Shield, Ray of Sickness

2nd Level (5 slots): Invisibility, Ray of Enfeeblement, Wither and Bloom, Arcane Lock, Blur, See Invisibility, Spider Climb

3rd Level (3 slots): Vampiric Touch, Spirit Shroud, Animate Dead, Bestow Curse, Counterspell, Fear, Major Image, Pulse Wave, Speak with Dead, Spirit Shroud

4th Level (3 slots): Blight, Shadow of Moil, Dimension Door, Gravity Sinkhole, Private Sanctum, Vitriolic Sphere

5th Level (3 slots): Contagion, Raise Dead, Danse Macabre, Negative Energy Flood, Synaptic Static

6th Level (2 slots): Harm, Circle of Death, Eyebite, Flesh to Stone, Forbiddance, Create Undead

7th Level (2 slot): Finger of Death, Magnificent Mansion, Forcecage, Regenerate, Reverse Gravity, Simulacrum

8th Level (1 slot): Clone, Glibness, Maze

9th Level (1 slot): Time Ravage, Foresight, Psychic Scream, Ravenous Void

Ivory Claw Staff. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 3) bludgeoning damage plus 3 (1d6) necrotic damage.

Consume Vitality (Recharge on 5-6). Each Creature within 30 ft. of Aceryic must make a DC 16 Constitution Saving throw. On a failed save, the creatures take 30 (6d10) necrotic damage, and Aceryic heals for the total amount done.

Aceryic can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Aceryic regains spent legendary actions at the start of it's turn.

Quick Fingers. Aceryic can cast any of his spells at or below 5th level.

Disengage. Aceryic can disengage from combat and move up to half his movement speed.

Commander. Aceryic can force all fiends and undead within 60 ft. to focus their efforts on a particular enemy.

Consume Vitality (Costs 2 Actions if Available). Each Creature within 30 ft. of Aceryic must make a DC 15 Constitution Saving throw. On a failed save, the creatures take 30 (6d10) necrotic damage, and Aceryic heals for the total amount done.